Method for efficient soluble expression and purification of recombinant human interleukin-15

Periplasmic expression of recombinant proteins ensures the production of biologically active proteins in a correctly folded state with several key advantages. This research focused on the in-frame cloning of rhIL-15 in pET-20 (+) vector with pelB-leader sequence to direct the protein to the bacterial periplasm. The target construct periplasmic expression was evaluated in four strains, BL21 (DE3), BL21 (DE3) pLysS, Rosetta 2 (DE3) and Rosetta-gami 2 (DE3). Soluble periplasmic expression of IL-15 was highest in Rosetta-gami 2 (DE3) followed by Rossetta 2 (DE3) whereas negligible expression was observed with rest of two expression host. Best expression clone was selected for purification by dye ligand affinity chromatography. Purified rhIL-15 was characterized by SDS-PAGE, Western blotting and SEC-HPLC. This is the first report of functional recombinant human interleukin-15 being expressed and purified with yield of 120 mg/L in the periplasmic space of E. coli.

Circulating tumor DNA in blood: Future genomic biomarkers for cancer detection

Cancer is characterized by Darwinian evolution and is a primary cause of mortality and morbidity around the globe. Over the preceding decade, the treatment of cancer has been markedly improved by many targeted therapies, but these treatments have given birth to new challenges and issues. Clonal evolution and tumor heterogeneity present a significant challenge in designing cancer therapies. Fortunately, these restrictions have been overcome by technological advancements allowing us to track both genetic and epigenetic aberrations. Cell-free circulating tumor DNA (ctDNA) analysis, or "liquid biopsy" from a blood sample, provides the opportunity to track the genetic landscape of cancerous lesions. This review focuses on ctDNA analysis as a noninvasive method and versatile biomarker for cancer treatment and technological advancements for ctDNA analysis. This method may able to cope with all the challenges associated with previous cancer therapies and has the potential to monitor minimal residual disease, tumor burden, and therapy response and provide rapid detection of relapse. However, there are many challenges that still need to be addressed. Future prognosis, diagnosis, and analysis of ctDNA require reproducibility and accuracy of results, which are not possible without the validation and optimization of procedures. Integrated digital error suppression has thus far shown promise in the detection of ctDNA in cancer.

HIV Diagnosis and Treatment through Advanced Technologies

Human immunodeficiency virus (HIV) is the chief contributor to global burden of disease. In 2010, HIV was the fifth leading cause of disability-adjusted life years in people of all ages and leading cause for people aged 30-44 years. It is classified as a member of the family Retroviridae and genus Lentivirus based on the biological, morphological, and genetic properties. It infects different cells of the immune system, such as CD4+ T cells (T-helper cells), dendritic cells, and macrophages. HIV has two subtypes: HIV-1 and HIV-2. Among these strains, HIV-1 is the most virulent and pathogenic. Advanced diagnostic methods are exploring new ways of treatment and contributing in the reduction of HIV cases. The diagnostic techniques like PCR, rapid test, EIA, p24 antigen, and western blot have markedly upgraded the diagnosis of HIV. Antiretroviral therapy and vaccines are promising candidates in providing therapeutic and preventive regimes, respectively. Invention of CRISPR/Cas9 is a breakthrough in the field of HIV disease management.

Microbiological Load of Ethylene Oxide Sterilized Medical Devices and its Elimination by Cobalt 60 Source

OBJECTIVE

To determine the residing microbial flora of ethylene oxide (EtO) sterilized medical devices and optimization of safe dose of gamma radiation (Cobalt 60 source) for the complete elimination of microbial load.

STUDY DESIGN

Experimental study.

PLACE AND DURATION OF STUDY

Department of Biotechnology, Lahore College for Women University, Lahore, Pakistan from September 2014 to June 2015.

METHODOLOGY

Thirty-six samples of EtO sterilized medical devices of same batch of three different companies were collected for this study. Isolation and enumeration of microbes were done by using different selective and differential media. Gram staining and biochemically characterization by API 20 (Bio Merieux, France) kit was done for identification of the microorganisms. The medical devices having high microbial load were sent to Pakistan Radiation Services (PARAS) for gamma irradiations at 3 different selected doses (20 KGy, 25 KGy, and 30 KGy).

RESULTS

Different types of Gram positive bacteria (Staphylococcus epidermidis, Staphylococcus aureus andBacillus subtilis) were isolated from the EtO sterilized samples. Gram negative bacteria and fungi were not detected on these medical devices. Gamma irradiations results showed that 30 KGy was optimized dose for complete elimination of microbial flora on endotracheal, Nelaton, and tracheostomy tubes.

CONCLUSION

Gamma radiations (Co 60 source) effectively decontaminate the microbial flora on the equipment previously sterilized by the ethylene oxide gas; and 30 KGy is the optimized dose for all these medical devices.

Molybdenum cofactor deficiency in a Malaysian child

Molybdenum cofactor deficiency is a rare autosomal recessive disorder with devastating neurological manifestations, characterised by neonatal-onset encephalopathy mimicking hypoxic-ischaemic insult, intractable seizure, and feeding and respiratory difficulties. It is often fatal in the early life. We report an affected 8-year-old boy, who presented with severe neurological manifestations since birth, but without clinically-significant seizure. Molybdenum cofactor deficiency must be included in the differential diagnosis of patients presenting with unexplained encephalopathy in the newborn period, and whose neuroimaging findings are consistent with hypoxic ischaemic encephalopathy. The classic laboratory hallmark of this disorder is low serum uric acid, positive urine sulphite dipstick test, and elevated urinary S-sulphocysteine, hypoxanthine and xanthine.

Supernumerary derivative (22) syndrome resulting from a maternal balanced translocation

Supernumerary derivative (22) syndrome is one of the rare genomic syndromes. It is characterised by severe mental retardation, microcephaly, failure to thrive, ear anomalies, preauricular tags or sinus, cleft palate or high arch palate, microganathia, renal anomalies, congenital cardiac defects and genital abnormalities in males. In 99 percent of the cases, one of the parents is a balanced carrier of a translocation between chromosome 11 and chromosome 22. We report the first known case, a female neonate, of supernumerary derivative (22) syndrome from Malaysia.